Thin-film magnetic head and method of manufacturing same

ABSTRACT

A thin-film magnetic head comprises a reproducing head and a recording head. The reproducing head comprises: a GMR element; a bottom shield layer and a top shield layer for shielding the GMR element; conductive layers connected to the GMR element; and shield gap films formed between the shield layers. Each of the shield gap films is made up of a plurality of thin alumina films stacked that are formed by performing the step of forming a thin alumina film by low pressure CVD, for example, a plurality of times.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a thin-film magnetic head havingat least one of an induction-type electromagnetic transducer and amagnetoresistive element, and to a method of manufacturing such athin-film magnetic head.

[0003] 2. Description of the Related Art

[0004] Performance improvements in thin-film magnetic heads have beensought as areal recording density of hard disk drives has increased.Such thin-film magnetic heads include composite thin-film magnetic headsthat have been widely used. A composite head is made of a layeredstructure including a recording head having an induction magnetictransducer for writing and a reproducing head having a magnetoresistive(MR) element for reading. MR elements include an anisotropicmagnetoresistive (AMR) element that utilizes the AMR effect and a giantmagnetoresistive (GMR) element that utilizes the GMR effect. Areproducing head using an AMR element is called an AMR head or simply anMR head. A reproducing head using a GMR element is called a GMR head. AnAMR head is used as a reproducing head where areal density is more than1 gigabit per square inch. A GMR head is used as a reproducing headwhere areal density is more than 3 gigabits per square inch. It is GMRheads that have been most widely used recently.

[0005] The performance of the reproducing head is improved by replacingthe AMR film with a GMR film and the like having an excellentmagnetoresistive sensitivity. Alternatively, a pattern width such as thereproducing track width and the MR height, in particular, may beoptimized. The MR height is the length (height) between an end of the MRelement located in the air bearing surface and the other end. The airbearing surface is a surface of the thin-film magnetic head facingtoward a magnetic recording medium.

[0006] Performance improvements in a recording head are also required asthe performance of a reproducing head is improved. It is required toincrease the recording track density in order to increase the arealdensity among the performance characteristics of the recording head. Toachieve this, it is required to implement a recording head of a narrowtrack structure wherein the width of top and bottom poles sandwichingthe recording gap layer on a side of the air bearing surface is reduceddown to microns or a submicron order. This width is one of the factorsthat determine the recording head performance. Semiconductor processtechniques are utilized to implement such a structure. Another factor isa pattern width such as the throat height, in particular. The throatheight is the length (height) of pole portions, that is, portions ofmagnetic pole layers facing each other with a recording gap layer inbetween, between the air-bearing-surface-side end and the other end. Areduction in throat height is desired in order to improve the recordinghead performance. The throat height is controlled by an amount oflapping when the air bearing surface is processed.

[0007] As thus described, it is important to fabricate well-balancedrecording and reproducing heads to improve the performance of thethin-film magnetic head.

[0008] In order to implement a thin-film magnetic head that achieveshigh recording density, the requirements for the reproducing headinclude a reduction in reproducing track width, an increase inreproducing output, and a reduction in noise. The requirements for therecording head include a reduction in recording track width, animprovement in overwrite property that is a parameter indicating one ofcharacteristics when data is written over existing data, and animprovement in nonlinear transition shift (NLTS).

[0009] Reference is now made to FIG. 16A to FIG. 22A and FIG. 16B toFIG. 22B to describe an example of a manufacturing method of arelated-art thin-film magnetic head element. FIG. 16A to FIG. 22A arecross sections each orthogonal to the air bearing surface. FIG. 16B toFIG. 22B are cross sections of the pole portions each parallel to theair bearing surface.

[0010] According to the manufacturing method, as shown in FIG. 16A andFIG. 16B, an insulating layer 102 made of alumina (Al₂O₃), for example,having a thickness of about 5 to 10 μm, is deposited on a substrate 101made of aluminum oxide and titanium carbide (Al₂O₃—TiC), for example.Next, on the insulating layer 102, a bottom shield layer 103 made of amagnetic material and having a thickness of 2 to 3 μm, for example, isformed for a reproducing head.

[0011] Next, as shown in FIG. 17A and FIG. 17B, a shield gap film 104 amade of an insulating material such as alumina and having a thickness of10 to 20 nm, for example, is formed through sputtering, for example, onthe bottom shield layer 103. Next, a shield gap film 104 b made of aninsulating material such as alumina and having a thickness of 100 nm,for example, is formed through sputtering, for example, on the shieldgap film 104 a except a region where a GMR element described later willbe formed. The shield gap film 104 b is provided for preventing a shortcircuit between the GMR element and the bottom shield layer 103.

[0012] Next, on the shield gap film 104 b, a film having a thickness of40 to 50 nm, for example, to make up the GMR element for reproduction isformed through a method such as sputtering. This film is etched with aphotoresist pattern not shown as a mask to form the GMR element 105.

[0013] Next, a pair of conductive layers (that may be called leads) 106are formed by liftoff through the use of the above-mentioned photoresistpattern. The conductive layers 106 are electrically connected to the GMRelement 105. The photoresist pattern is then removed.

[0014] Next, as shown in FIG. 18A and FIG. 18B, a shield gap film 107 amade of an insulating material such as alumina and having a thickness of10 to 20 nm, for example, is formed through sputtering, for example, onthe shield gap films 104 a and 104 b, the GMR element 105 and theconductive layers 106. The GMR element 105 is embedded in the shield gapfilms 104 a and 107 a. Next, a shield gap film 107 b made of aninsulating material such as alumina and having a thickness of 100 nm,for example, is formed through a method such as sputtering on the shieldgap film 107 a except the neighborhood of the GMR element 105.

[0015] Next, as shown in FIG. 19A and FIG. 19B, on the shield gap films107 a and 107 b, a top-shield-layer-cum-bottom-pole-layer (called a topshield layer in the following description) 108 is formed. The top shieldlayer 108 has a thickness of about 3 μm and is made of a magneticmaterial and used for both the reproducing head and the recording head.

[0016] Next, as shown in FIG. 20A and FIG. 20B, a recording gap layer109 made of an insulating film such as an alumina film and having athickness of 0.2 μm, for example, is formed on the top shield layer 108.Next, a portion of the recording gap layer 109 located in the center ofthe region where a thin-film coil described later is to be formed isetched to form a contact hole for making a magnetic path. Next, a toppole tip 110 for the recording head is formed on the recording gap layer109 in the pole portion. The top pole tip 110 is made of a magneticmaterial and has a thickness of 1.0 to 1.5 μm. At the same time, amagnetic layer 119 made of a magnetic material is formed for making themagnetic path in the contact hole for making the magnetic path.

[0017] Next, the recording gap layer 109 and a part of the top shieldlayer 108 are etched through ion milling, using the top pole tip 110 asa mask. As shown in FIG. 20B, the structure is called a trim structurewherein the sidewalls of the top pole portion (the top pole tip 110),the recording gap layer 109, and a part of the top shield layer 108 areformed vertically in a self-aligned manner.

[0018] Next, an insulating layer 111 of alumina, for example, having athickness of about 3 μm is formed over the entire surface. Theinsulating layer 111 is polished to the surfaces of the top pole tip 110and the magnetic layer 119 and flattened.

[0019] Next, as shown in FIG. 21A and FIG. 21B, on the flattenedinsulating layer 111 a first layer 112 of the thin-film coil is made forthe induction-type recording head. The first layer 112 of the coil ismade of copper (Cu), for example. Next, a photoresist layer 113 isformed into a specific shape on the insulating layer 111 and the firstlayer 112 of the coil. Next, a second layer 114 of the thin-film coil isformed on the photoresist layer 113. Next, a photoresist layer 115 isformed into a specific shape on the photoresist layer 113 and the secondlayer 114 of the coil.

[0020] Next, as shown in FIG. 22A and FIG. 22B, a top pole layer 116 forthe recording head is formed on the top pole tip 110, the photoresistlayers 113 and 115 and the magnetic layer 119. The top pole layer 116 ismade of a magnetic material such as Permalloy. Next, an overcoat layer117 of alumina, for example, is formed to cover the top pole layer 116.Finally, machine processing of the slider including the forgoing layersis performed to form the air bearing surface 118 of the thin-filmmagnetic head including the recording head and the reproducing head. Thethin-film magnetic head is thus completed.

[0021]FIG. 23 is a top view of the thin-film magnetic head shown in FIG.22A and FIG. 22B. The overcoat layer 117 and the other insulating layersand film are omitted in FIG. 27.

[0022] In order to improve the performance characteristics of a harddisk drive, such as areal recording density, in particular, a method ofincreasing linear recording density and a method of increasing trackdensity may be taken. To design a high-performance hard disk drive,specific measures taken for implementing the recording head, thereproducing head or the thin-film magnetic head as a whole depend onwhether linear recording density or track density is emphasized. Thatis, if priority is given to track density, a reduction in track width isrequired for both recording head and reproducing head, for example. Ifpriority is given to linear recording density, it is required for thereproducing head to improve the reproducing output and to reduce thehalf width of the reproducing output. Moreover, it is required to reducethe distance between the hard disk platter and the slider (hereinaftercalled a magnetic space). To achieve areal density of 20 to 30 gigabitsper square inch, a magnetic space of 15 to 25 nm, for example, isrequired.

[0023] Consideration will now be given to the measures taken whenpriority is given to linear recording density. Among the factors thatcontribute to improvements in linear recording density, a reduction inmagnetic space is achieved by reducing the amount of floating of theslider. The amount of floating of the slider depends mainly on thedesign, processing method, lapping method and so on of the slider.

[0024] Among the factors that contribute to improvements in linearrecording density, an improvement in reproducing output is achievedmainly by replacing the AMR film with a GMR film and the like having anexcellent magnetoresistive sensitivity. It is known that another factor,that is, a reduction in half width of the reading output, is achieved byreducing the distance between the bottom shield layer and the top shieldlayer (hereinafter called the shield gap length). It is possible tocontrol the shield gap length in the steps of manufacturing thethin-film magnetic head.

[0025] The problems arising when the shield gap length is reduced willnow be described. To implement areal recording density of about 10gigabits per square inch, an appropriate shield gap length is 0.11 to0.14 μm (110 to 140 nm). However, a shield gap length of 0.07 to 0.09 μm(70 to 90 nm) is required for implementing areal recording density of 30to 40 gigabits per square inch.

[0026] It is difficult to reduce the thickness of the MR element sincethis thickness is determined by factors such as the reading outputrequired. Therefore, in order to reduce the shield gap length, it isrequired to reduce the thickness of the shield gap film provided betweenthe MR element and the bottom shield layer, and the thickness of theshield gap film provided between the MR element and the top shieldlayer.

[0027] A case is assumed wherein a shield gap length of 60 to 70 nm isrequired to implement areal recording density of 40 gigabits per squareinch. In this case, if the thickness of the MR element is 40 nm, thethickness of the shield gap films each of which is provided between theMR element and the bottom shield layer and between the MR element andthe top shield layer, respectively, is required to be 10 to 15 nm.

[0028] In prior art the shield gap film is made of an alumina filmformed through sputtering performed in a plasma atmosphere through theuse of an apparatus such as a radio frequency (RF) sputtering apparatusor an electron cyclotron resonance (ECR) sputtering apparatus.

[0029] However, a reduction in the thickness of the prior-art shield gapfilm formed through sputtering is limited to about 20 nm. That is, ifthe thickness of the prior-art shield gap film is smaller than 20 nm,the insulation strength is 5 to 7 volts or smaller so that static damageis likely to occur. If the thickness of the prior-art shield gap film isreduced down to about 10 to 15 nm, not only the insulation strength ismade smaller but also pinholes are likely to occur. If static damage isdone to the shield gap film or pinholes are made in the shield gap film,a short circuit is developed between the MR element and the bottomshield layer or the top shield layer. As a result, the reading outputsignal carries noise, and it is impossible to obtain a proper readingoutput signal in some cases.

[0030] In addition, the prior-art shield gap film exhibits bad stepcoverage. Therefore, pinholes or faulty insulation frequently occurs inportions having projections and depressions, in particular, such as theneighborhood of the pattern edge of the MR element or the leadsconnected to the MR element.

[0031] As thus described, it is difficult in prior art to form theshield gap film that is thin and exhibits high qualities, that is,closely packed and has an even thickness, greater insulation strengthand excellent step coverage. Therefore, it is difficult to reduce theshield gap length of the prior art thin-film magnetic head, and toreduce the half width of the reading output and to improve the recordingdensity. In addition, since it is difficult in prior art to form ahigh-quality and thin shield gap film, the yield of thin-film magneticheads for high density recording is low.

[0032] Although the problems arising when the shield gap film is formedhave been described so far, similar problems are found in formation oflayers such as the recording gap layer, an insulating film of athin-film magnetic head wherein the recording head and the reproducinghead are isolated from each other by the insulating film, or aninsulating layer for isolating turns of the coil.

OBJECT AND SUMMARY OF THE INVENTION

[0033] It is an object of the invention to provide a thin-film magnetichead and a method of manufacturing the same for improving theperformance characteristics and the yield by providing a high-qualityinsulating film.

[0034] A first thin-film magnetic head of the invention comprises: amedium facing surface that faces toward a recording medium; amagnetoresistive element; a first shield layer and a second shield layerfor shielding the magnetoresistive element, the shield layers havingportions located on a side of the medium facing surface and opposed toeach other, the magnetoresistive element being placed between theseportions of the shield layers; a first shield gap film, provided betweenthe magnetoresistive element and the first shield layer, for insulatingthe magnetoresistive element and the first shield layer from each other;and a second shield gap film, provided between the magnetoresistiveelement and the second shield layer, for insulating the magnetoresistiveelement and the second shield layer from each other. At least one of thefirst and second shield gap films is made of a plurality of insulatingfilms stacked that are formed by chemical vapor deposition.

[0035] A second thin-film magnetic head of the invention comprises: amedium facing surface that faces toward a recording medium; a firstmagnetic layer including a pole portion and a second magnetic layerincluding a pole portion, the first and second magnetic layers beingmagnetically coupled to each other, the pole portions being opposed toeach other and placed in regions of the magnetic layers on a side of themedium facing surface, each of the magnetic layers including at leastone layer; a gap layer provided between the pole portions of the firstand second magnetic layers; and a thin-film coil at least a part ofwhich is placed between the first and second magnetic layers, the atleast part of the coil being insulated from the first and secondmagnetic layers. The gap layer is made of a plurality of insulatingfilms stacked that are formed by chemical vapor deposition.

[0036] A third thin-film magnetic head of the invention comprises: amedium facing surface that faces toward a recording medium; areproducing head; a recording head; and an isolation film formagnetically isolating the reproducing head and the recording head fromeach other. The reproducing head incorporates: a magnetoresistiveelement; a first shield layer and a second shield layer for shieldingthe magnetoresistive element, the shield layers having portions locatedon a side of the medium facing surface and opposed to each other, themagnetoresistive element being placed between these portions of theshield layers; a first shield gap film, provided between themagnetoresistive element and the first shield layer, for insulating themagnetoresistive element and the first shield layer from each other; anda second shield gap film, provided between the magnetoresistive elementand the second shield layer, for insulating the magnetoresistive elementand the second shield layer from each other. The recording headincorporates: a first magnetic layer including a pole portion and asecond magnetic layer including a pole portion, the first and secondmagnetic layers being magnetically coupled to each other, the poleportions being opposed to each other and placed in regions of themagnetic layers on a side of the medium facing surface, each of themagnetic layers including at least one layer; a gap layer providedbetween the pole portions of the first and second magnetic layers; and athin-film coil at least a part of which is placed between the first andsecond magnetic layers, the at least part of the coil being insulatedfrom the first and second magnetic layers. The isolation film is made ofa plurality of insulating films stacked that are formed by chemicalvapor deposition.

[0037] A fourth thin-film magnetic head of the invention comprises: amedium facing surface that faces toward a recording medium; a firstmagnetic layer including a pole portion and a second magnetic layerincluding a pole portion, the first and second magnetic layers beingmagnetically coupled to each other, the pole portions being opposed toeach other and placed in regions of the magnetic layers on a side of themedium facing surface, each of the magnetic layers including at leastone layer; a gap layer provided between the pole portions of the firstand second magnetic layers; a thin-film coil at least a part of which isplaced between the first and second magnetic layers, the at least partof the coil being insulated from the first and second magnetic layers;and a coil insulating layer for insulating neighboring ones of turns ofthe coil from each other. The coil insulating layer is made of aplurality of insulating films stacked that are formed by chemical vapordeposition.

[0038] According to the first to fourth thin-film magnetic heads of theinvention, one of the first and second shield gap films, the gap layer,the isolation film, or the coil insulating layer is made of a pluralityof insulating films stacked that are formed by chemical vapordeposition, and exhibits high quality.

[0039] According to the first to fourth thin-film magnetic heads of theinvention, the insulating films formed by chemical vapor deposition maybe alumina films.

[0040] A first method of the invention is provided for manufacturing athin-film magnetic head comprising: a medium facing surface that facestoward a recording medium; a magnetoresistive element; a first shieldlayer and a second shield layer for shielding the magnetoresistiveelement, the shield layers having portions located on a side of themedium facing surface and opposed to each other, the magnetoresistiveelement being placed between these portions of the shield layers; afirst shield gap film, provided between the magnetoresistive element andthe first shield layer, for insulating the magnetoresistive element andthe first shield layer from each other; and a second shield gap film,provided between the magnetoresistive element and the second shieldlayer, for insulating the magnetoresistive element and the second shieldlayer from each other. The method includes the steps of: forming thefirst shield layer; forming the first shield gap film on the firstshield layer; forming the magnetoresistive element on the first shieldgap film; forming the second shield gap film on the magnetoresistiveelement; and forming the second shield layer on the second shield gapfilm. At least one of the first and second shield gap films is formed bystacking a plurality of insulating films formed by chemical vapordeposition.

[0041] A second method of the invention is provided for manufacturing athin-film magnetic head comprising: a medium facing surface that facestoward a recording medium; a first magnetic layer including a poleportion and a second magnetic layer including a pole portion, the firstand second magnetic layers being magnetically coupled to each other, thepole portions being opposed to each other and placed in regions of themagnetic layers on a side of the medium facing surface, each of themagnetic layers including at least one layer; a gap layer providedbetween the pole portions of the first and second magnetic layers; and athin-film coil at least a part of which is placed between the first andsecond magnetic layers, the at least part of the coil being insulatedfrom the first and second magnetic layers. The method includes the stepsof: forming the first magnetic layer; forming the gap layer on the firstmagnetic layer; forming the second magnetic layer on the gap layer; andforming the thin-film coil. The gap layer is formed by stacking aplurality of insulating films formed by chemical vapor deposition.

[0042] A third method of the invention is provided for manufacturing athin-film magnetic head comprising: a medium facing surface that facestoward a recording medium; a reproducing head; a recording head; and anisolation film for magnetically isolating the reproducing head and therecording head from each other. The reproducing head incorporates: amagnetoresistive element; a first shield layer and a second shield layerfor shielding the magnetoresistive element, the shield layers havingportions located on a side of the medium facing surface and opposed toeach other, the magnetoresistive element being placed between theseportions of the shield layers; a first shield gap film, provided betweenthe magnetoresistive element and the first shield layer, for insulatingthe magnetoresistive element and the first shield layer from each other;and a second shield gap film, provided between the magnetoresistiveelement and the second shield layer, for insulating the magnetoresistiveelement and the second shield layer from each other. The recording headincorporates: a first magnetic layer including a pole portion and asecond magnetic layer including a pole portion, the first and secondmagnetic layers being magnetically coupled to each other, the poleportions being opposed to each other and placed in regions of themagnetic layers on a side of the medium facing surface, each of themagnetic layers including at least one layer; a gap layer providedbetween the pole portions of the first and second magnetic layers; and athin-film coil at least a part of which is placed between the first andsecond magnetic layers, the at least part of the coil being insulatedfrom the first and second magnetic layers. The method includes the stepsof: forming the reproducing head; forming the recording head; andforming the isolation film. The isolation film is formed by stacking aplurality of insulating films formed by chemical vapor deposition.

[0043] A fourth method of the invention is provided for manufacturing athin-film magnetic head comprising: a medium facing surface that facestoward a recording medium; a first magnetic layer including a poleportion and a second magnetic layer including a pole portion, the firstand second magnetic layers being magnetically coupled to each other, thepole portions being opposed to each other and placed in regions of themagnetic layers on a side of the medium facing surface, each of themagnetic layers including at least one layer; a gap layer providedbetween the pole portions of the first and second magnetic layers; athin-film coil at least a part of which is placed between the first andsecond magnetic layers, the at least part of the coil being insulatedfrom the first and second magnetic layers; and a coil insulating layerfor insulating neighboring ones of turns of the coil from each other.The method includes the steps of: forming the first magnetic layer;forming the gap layer on the first magnetic layer; forming the secondmagnetic layer on the gap layer; forming the thin-film coil; and formingthe coil insulating layer. The coil insulating layer is formed bystacking a plurality of insulating films formed by chemical vapordeposition.

[0044] According to the first to fourth methods of the invention, theinsulating films formed by the chemical vapor deposition may be aluminafilms.

[0045] According to the first to fourth methods of the invention, thechemical vapor deposition may be low pressure chemical vapor deposition,or may be plasma chemical vapor deposition or atmospheric pressurechemical vapor deposition.

[0046] According to the first to fourth methods of the invention, theinsulating films formed by the chemical vapor deposition may be formedthrough the use of a plurality of chambers.

[0047] According to the first to fourth methods of the invention, theinsulating films formed by the chemical vapor deposition may be formedthrough intermittently injecting a material for making the films. Inthis case, the insulating films formed by the chemical vapor depositionmay be alumina films formed through intermittently injecting H₂O, N₂O orH₂O₂ which is the material for making the films and Al(CH₃)₃ or AlCl₃which is the material for making the films in an alternate manner.

[0048] According to the first to fourth methods of the invention, theinsulating films formed by the chemical vapor deposition may be formedat a temperature in a range of 100 to 350° C.

[0049] Other and further objects, features and advantages of theinvention will appear more fully from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0050]FIG. 1A and FIG. 1B are cross sections for illustrating a step ina method of manufacturing a thin-film magnetic head of a firstembodiment of the invention.

[0051]FIG. 2A and FIG. 2B are cross sections for illustrating a stepthat follows FIG. 1A and FIG. 1B.

[0052]FIG. 3A and FIG. 3B are cross sections for illustrating a stepthat follows FIG. 2A and FIG. 2B.

[0053]FIG. 4A and FIG. 4B are cross sections for illustrating a stepthat follows FIG. 3A and FIG. 3B.

[0054]FIG. 5A and FIG. 5B are cross sections for illustrating a stepthat follows FIG. 4A and FIG. 4B.

[0055]FIG. 6A and FIG. 6B are cross sections for illustrating a stepthat follows FIG. 2A and FIG. 2B.

[0056]FIG. 7A and FIG. 7B are cross sections for illustrating a stepthat follows FIG. 6A and FIG. 6B.

[0057]FIG. 8A and FIG. 8B are cross sections of the thin-film magnetichead of the first embodiment.

[0058]FIG. 9 is a top view of the thin-film magnetic head of the firstembodiment.

[0059]FIG. 10 illustrates a first example of a method of forming amultilayer CVD insulating film of the first embodiment of the invention.

[0060]FIG. 11 illustrates a second example of the method of forming themultilayer CVD insulating film of the first embodiment.

[0061]FIG. 12 is a plot for showing the result of experiment performedfor comparing the insulation strength of an insulating film formedthrough sputtering and that of the multilayer CVD insulating film of thefirst embodiment of the invention.

[0062]FIG. 13 is a plot for illustrating an example of waveform ofreading output of the thin-film magnetic head of the first embodiment.

[0063]FIG. 14A and FIG. 14B are cross sections of a thin-film magnetichead of a second embodiment of the invention.

[0064]FIG. 15A and FIG. 15B are cross sections of a thin-film magnetichead of a third embodiment of the invention.

[0065]FIG. 16A and FIG. 16B are cross sections for illustrating a stepin a method of manufacturing a thin-film magnetic head of related art.

[0066]FIG. 17A and FIG. 17B are cross sections for illustrating a stepthat follows FIG. 16A and FIG. 16B.

[0067]FIG. 18A and FIG. 18B are cross sections for illustrating a stepthat follows FIG. 17A and FIG. 17B.

[0068]FIG. 19A and FIG. 19B are cross sections for illustrating a stepthat follows FIG. 18A and FIG. 18B.

[0069]FIG. 20A and FIG. 20B are cross sections for illustrating a stepthat follows FIG. 19A and FIG. 19B.

[0070]FIG. 21A and FIG. 21B are cross sections for illustrating a stepthat follows FIG. 20A and FIG. 20B.

[0071]FIG. 22A and FIG. 22B are cross sections for illustrating a stepthat follows FIG. 21A and FIG. 21B.

[0072]FIG. 23 is a top view of the related-art thin-film magnetic head.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0073] Preferred embodiments of the invention will now be described indetail with reference to the accompanying drawings.

First Embodiment

[0074] Reference is now made to FIG. 1A to FIG. 8A, FIG. 1B to FIG. 8B,and FIG. 9 to describe a thin-film magnetic head and a method ofmanufacturing the same of a first embodiment of the invention. FIG. 1Ato FIG. 8A are cross sections each orthogonal to the air bearingsurface. FIG. 1B to FIG. 8B are cross sections of the pole portions ofthe head parallel to the air bearing surface.

[0075] In the method, as shown in FIG. 1A and FIG. 1B, an insulatinglayer 2 made of alumina (Al₂O₃), for example, of about 5 to 10 μm inthickness is deposited on a substrate 1 made of aluminum oxide andtitanium carbide (Al₂O₃—TiC), for example. Next, on the insulating layer2, a bottom shield layer 3 is formed for the reproducing head. Thebottom shield layer 3 is made of a magnetic material and has a thicknessof 2 to 3 μm, for example.

[0076] Next, as shown in FIG. 2A and FIG. 2B, a shield gap film 4 a asan insulating film having a thickness of 10 to 15 nm, for example, isformed on the bottom shield layer 3. The shield gap film 4 a is made ofthe insulating film in which a plurality of thin alumina films arestacked, each of the alumina films being formed through chemical vapordeposition (CVD). This insulating film is hereinafter called themultilayer CVD insulating film. The method of forming the shield gaplayer 4 a will be described later in detail.

[0077] Next, a shield gap film 4 b, as an insulating film made of aninsulating material such as alumina, having a thickness of 100 nm, forexample, is formed on the shield gap film 4 a except a region where aGMR element described later will be formed. The shield gap film 4 b maybe an insulating film formed through sputtering or a multilayer CVDinsulating film. The shield gap film 4 b is provided for preventing ashort circuit between the GMR element and the bottom shield layer 3.

[0078] Next, on the shield gap film 4 b, a film having a thickness of 40to 50 nm, for example, for making up the GMR element for reproduction isformed through a method such as sputtering. This film is etched with aphotoresist pattern not shown as a mask to form the GMR element 5.

[0079] Next, a pair of conductive layers (that may be called leads) 6are formed by liftoff through the use of the above-mentioned photoresistpattern. The conductive layers 6 are electrically connected to the GMRelement 5. The photoresist pattern is then removed.

[0080] Next, as shown in FIG. 3A and FIG. 3B, a shield gap film 7 a, asan insulating film, having a thickness of 10 to 20 nm, for example, isformed on the shield gap films 4 a and 4 b, the GMR element 5 and theconductive layers 6. The GMR element 5 is embedded in the shield gapfilms 4 a and 7 a. The shield gap film 7 a is made of a multilayer CVDinsulating film. The method of forming the shield gap film 7 a will bedescribed later in detail.

[0081] Next, a shield gap film 7 b as an insulating film made of aninsulating material such as alumina and having a thickness of 100 nm,for example, is formed on the shield gap film 7 a except theneighborhood of the GMR element 5. The shield gap film 7 b may be aninsulating film formed through sputtering or a multilayer CVD insulatingfilm. The shield gap film 7 b is provided for preventing a short circuitbetween the GMR element 5 and a top shield layer described later.

[0082] Next, as shown in FIG. 4A and FIG. 4B, on the shield gap films 7a and 7 b, a top-shield-layer-cum-bottom-pole-layer (called a top shieldlayer in the following description) 8 is formed. The top shield layer 8has a thickness of about 3 μm and is made of a magnetic material andused for both the reproducing head and the recording head.

[0083] Next, as shown in FIG. 5A and FIG. 5B, a recording gap layer 9made of an insulating film such as an alumina film and having athickness of 0.1 to 0.2 μm, for example, is formed on the top shieldlayer 8. The gap layer 9 may be an insulating film formed throughsputtering or a multilayer CVD insulating film.

[0084] Next, on the recording gap layer 9, a thin-film coil 10 made ofcopper (Cu), for example, is formed through plating, for example, forthe induction-type recording head. For example, the line width of thecoil 10 is 0.5 to 0.8 μm, the space between neighboring ones of turns ofthe coil 10 is 0.5 μm, and the thickness of the coil 10 is 0.8 to 1.5μm.

[0085] Next, a photoresist layer 11 is formed into a specific shape onthe recording gap layer 9 and the coil 10. An end of the photoresistlayer 11 facing toward the air bearing surface (the medium facingsurface that faces toward a recording medium) 30 defines the throatheight.

[0086] Next, as shown in FIG. 6A and FIG. 6B, a portion of the recordinggap layer 9 located in the center of the region where the thin-film coil10 is formed is selectively etched to form a contact hole for making amagnetic path.

[0087] Next, a pole portion layer 12 a including the pole portion of thetop pole layer 12 is formed in a region extending from the top of a partof the recording gap layer 9 located in the pole portion to a part ofthe photoresist layer 11 close to the air baring surface 30. The poleportion layer 12 a has a thickness of 2.5 to 3.5 μm, for example. At thesame time, a magnetic layer 12 b having a thickness of 2.5 to 3.5 μm,for example, is formed in the above-mentioned contact hole. The top polelayer 12 is made up of the pole portion layer 12 a and the magneticlayer 12 b and a yoke portion layer described later. The magnetic layer12 b is provided for connecting the yoke portion layer to the top shieldlayer 8.

[0088] The pole portion layer 12 a and the magnetic layer 12 b of thetop pole layer 12 may be made of NiFe (80 weight % Ni and 20 weight %Fe), or NiFe (45 weight % Ni and 55 weight % Fe) as a high saturationflux density material and formed through plating, or may be made of amaterial such as FeN or FeZrN as a high saturation flux density materialthrough sputtering. Alternatively, a material such as CoFe or a Co-baseamorphous material as a high saturation flux density material may beused.

[0089] Next, the recording gap layer 9 and a part of the top shieldlayer 8 are etched through ion milling, for example, using the poleportion layer 12 a as a mask. As shown in FIG. 7B, the structure iscalled a trim structure wherein the sidewalls of the top pole portion(the pole portion layer 12 a), the recording gap layer 9, and a part ofthe top shield layer 8 are formed vertically in a self-aligned manner.The trim structure suppresses an increase in the effective track widthdue to expansion of a magnetic flux generated during writing in a narrowtrack.

[0090] Next, an insulating layer 13 of alumina, for example, having athickness of about 4 μm is formed over the entire surface. Theinsulating layer 13 is polished through chemical mechanical polishing(CMP), for example, to the surfaces of the pole portion layer 12 a andthe magnetic layer 12 b and flattened.

[0091] Next, as shown in FIG. 8A and FIG. 8B, the yoke portion layer 12c of the top pole layer 12 made of a magnetic material for the recordinghead is formed on the pole portion layer 12 a, the insulating layer 13and the magnetic layer 12 b. The yoke portion layer 12 c has a thicknessof 3 μm, for example. The yoke portion layer 12 c may be made of NiFe(80 weight % Ni and 20 weight % Fe) or a high saturation flux densitymaterial such as NiFe (45 weight % Ni and 55 weight % Fe) throughplating, or may be made of a material such as FeN or FeZrN as a highsaturation flux density material through sputtering. Alternatively, amaterial such as CoFe or a Co-base amorphous material as a highsaturation flux density material may be used. To improve the highfrequency characteristic, the yoke portion layer 12 c may be made of anumber of layers of inorganic insulating films and magnetic layers ofPermalloy, for example.

[0092] Next, an overcoat layer 14 of alumina, for example, having athickness of 20 to 40 μm, for example, is formed to cover the top polelayer 12. Finally, machine processing of the slider including theforgoing layers is performed to form the air bearing surface 30 of thethin-film magnetic head including the recording head and the reproducinghead. The thin-film magnetic head is thus completed.

[0093]FIG. 9 is a top view of the thin-film magnetic head shown in FIG.8A and FIG. 8B. The overcoat layer 14 and the other insulating layersand film are omitted in FIG. 9. The pole portion of the pole portionlayer 12 a located on a side of the air bearing surface 30 has a widthequal to the track width of the recording head.

[0094] In this embodiment the bottom shield layer 3 corresponds to thefirst shield layer of the invention. The top shield layer 8 correspondsto the second shield layer of the invention. Since the top shield layer8 functions as the bottom pole layer, too, the top shield layer 8corresponds to the first magnetic layer of the invention, too. The toppole layer 12 corresponds to the second magnetic layer of the invention,too. The shield gap film 4 a corresponds to the first shield gap film ofthe invention. The shield gap film 7 a corresponds to the second shieldgap film of the invention.

[0095] The thin-film magnetic head of this embodiment comprises the airbearing surface 30, that is, the medium facing surface that faces towarda recording medium, the reproducing head and the recording head(induction-type electromagnetic transducer). The reproducing headincludes the GMR element 5 and the bottom shield layer 3 and the topshield layer 8 for shielding the GMR element 5. Portions of the bottomshield layer 3 and the top shield layer 8 on a side of the air bearingsurface 30 are opposed to each other while the GMR element 5 is placedbetween these portions of the bottom shield layer 3 and the top shieldlayer 8. The reproducing head further includes: the conductive layers 6connected to the GMR element 5; the shield gap films 4 a and 4 bprovided between the bottom shield layer 3 and the GMR element 5together with the conductive layers 6; and the shield gap films 7 a and7 b provided between the top shield layer 8 and the GMR element 5together with the conductive layers 6.

[0096] The recording head includes the bottom pole layer (the top shieldlayer 8) and the top pole layer 12 magnetically coupled to each othereach of which includes at least one layer. The bottom pole layer and thetop pole layer 12 include pole portions opposed to each other andlocated in regions on a side of the air bearing surface 30. Therecording head further includes: the recording gap layer 9 placedbetween the pole portion of the bottom pole layer and the pole portionof the top pole layer 12; and the thin-film coil 10 at least a part ofwhich is placed between the bottom pole layer and the top pole layer 12,the at least part of the coil 10 being insulated from the bottom polelayer and the top pole layer 12.

[0097] The following is a description of two examples of the method offorming a multilayer CVD insulating film that is utilized as each of theshield gap films 4 a and 7 a of the embodiment of the invention.

[0098]FIG. 10 illustrates the first example of the method of forming amultilayer CVD insulating film. In this example the multilayer CVDinsulating film is formed by performing the step of making a thinalumina film by low pressure CVD a plurality of times. Such a method offorming an insulating film is described in ‘Microelectronic Engineering36’ (1997), pp. 91-94, for example.

[0099] In the first example, as shown in FIG. 10, a thin alumina film isformed on a substrate 60 through the use of a low pressure CVD apparatus50. This substrate 60 means a structure including the substrate 1 andthe layers stacked thereon in the steps preceding formation of theinsulating film to be obtained. In a chamber 51 of the low pressure CVDapparatus 50, a chuck 52 is provided for fixing the object on which thethin film is to be formed. A heater not shown for heating the chuck 52is provided below the chuck 52. The chamber 51 has two nozzles 53 and 54for injecting a material for making thin films into the chamber 51.

[0100] In the first example the substrate 60 is fixed on the top surfaceof the chuck 52 in the chamber 51 of the low pressure CVD apparatus 50.When a multilayer CVD insulating film is formed on the substrate 60, thechuck 52 and the substrate 60 are maintained at a temperature in therange of 100 to 350° C., or preferably in the range of 150 to 250° C.Therefore, thin alumina films making up the multilayer CVD insulatingfilm are formed at a temperature in the range of 100 to 350° C., orpreferably in the range of 150 to 250° C. The degree of vacuum insidethe chamber 51 is maintained at about 10³¹ ³ to 10⁻⁵ Pa.

[0101] In the first example the following steps are alternatelyrepeated. The step first taken is to inject a material for making a thinfilm, that is, H₂O, N₂O or H₂O₂ through the nozzle 53, for example, ontothe substrate 60 for a short period of time, the material being carriedby bubbles of a purge gas of N₂. The next step is to inject a materialfor making the thin film, that is, Al(CH₃)₃ (trimethylaluminum) or AlCl₃through the nozzle 54, for example, onto the substrate 60 for a shortperiod of time, the material being carried by bubbles of a purge gas ofN₂. In the first example the materials for making thin films areintermittently injected onto the substrate 60. The flow rate of oneinjection of H₂O, N₂O or H₂O₂ is 0.25 to 0.5 mg, for example. The flowrate of one injection of Al(CH₃)₃ or AlCl₃ is 0.1 to 0.2 mg, forexample. One cycle is the combination of one injection of H₂O, N₂O orH₂O₂ and one injection of Al(CH₃)₃ or AlCl₃. The duration of one cycleis about 2 seconds, for example. Through the cycle, an alumina film asthin as 0.1 to 0.2 nm, for example, is formed on the substrate 60 by achemical reaction between H₂O, N₂O or H₂O₂ and Al(CH₃)₃ or AlCl₃. In thefirst example a plurality of cycles are performed to stack a pluralityof thin alumina films. A multilayer CVD insulating film having a desiredthickness is thereby formed.

[0102]FIG. 11 illustrates the second example of the method of forming amultilayer CVD insulating film. In this example the multilayer CVDinsulating film is formed by performing the step of making a thinalumina film by CVD a plurality of times through the use of a pluralityof chambers. In the second example, as shown in FIG. 11, thin aluminafilms are formed on the substrate 60 through the use of a multi-chamberCVD apparatus 70. The CVD apparatus 70 comprises a plurality of chambers71 and a transfer device 72 for loading and unloading the object onwhich thin films are to be formed in and out of the chambers 71. Each ofthe chambers 71 is designed to form a desired thin film on the object byplasma CVD, for example.

[0103] In the second example the substrate 60 is transferred to one ofthe chambers 71 by the transfer device 72. In this chamber 71 a thinalumina film is formed on the substrate 60 through the use of O₂ andAl(CH₃)₃, for example. The degree of vacuum inside each of the chambers71 is maintained at about 10⁻³ Pa, for example. The substrate 60 in eachof the chambers 71 is maintained at a temperature in the range of 100 to350° C., or preferably in the range of 200 to 250° C. In each of thechambers 71 the alumina film formed on the substrate 60 has a thicknessof 0.5 to 1.5 nm, for example.

[0104] In the second example the substrate 60 on which the thin aluminafilm is formed as described above is transferred to another one of thechambers 71 by the transfer device 72. In this one of the chambers 71another alumina film is formed on the substrate 60 as in the first oneof the chambers 71. In the second example the substrate 60 istransferred among the chambers 71 in each of which a thin alumina filmis formed on the substrate 60 in a similar manner. According to thesecond example as thus described, the step of forming a thin aluminafilm is performed a plurality of times through the use of a plurality ofchambers 71. A multilayer CVD insulating film is thereby formed.

[0105] In the second example atmospheric CVD may be used instead ofplasma CVD.

[0106] The foregoing first and second examples are not limited to theinsulating films making up the shield gap films 4 a and 7 a but may beapplied to the insulating films making up the shield gap films 4 b and 7b and to the insulating film making up the recording gap layer 9.

[0107] Compared to an insulating film formed through sputtering, themultilayer CVD insulating film formed through the method such as theforegoing first or second example is more closely packed and has a moreeven thickness, greater insulation strength and better step coverageowing to the closely packed structure. Since the multilayer CVDinsulating film has such qualities, it is possible to reduce thethickness thereof without reducing the qualities, compared to theinsulating film formed through sputtering.

[0108] The following is a description of the result of experimentperformed for comparing center line average height Ra of an insulatingfilm formed through sputtering and that of the multilayer CVD insulatingfilm of the embodiment of the invention. The center line average heightRa indicates evenness of the thickness. In this experiment the averageheight Ra of the insulating film formed through sputtering and having athickness of 30 nm, and that of the multilayer CVD insulating filmhaving a thickness of 30 nm were obtained. The result was that theaverage height Ra of the insulating film formed through sputtering was0.216 nm while the average height Ra of the multilayer CVD insulatingfilm was 0.107 nm. This result shows that the evenness of the thicknessof the multilayer CVD insulating film was better than that of theinsulating film formed through sputtering.

[0109] Reference is now made to FIG. 12 to describe the result ofexperiment performed for comparing the insulation strength of aninsulating film formed through sputtering and that of the multilayer CVDinsulating film of the embodiment of the invention. FIG. 12 shows therelationship between the voltage applied to four types of insulatingfilms and the percentage of insulating films in which no punctureoccurred (which is indicated as yield in FIG. 12). The four types ofinsulating films were: an alumina film (indicated as ECR_15 in FIG. 12)having a thickness of 15 nm and formed through continuous sputteringthrough the use of an electron cyclotron resonance (ECR) sputteringapparatus; an alumina film (indicated as ECR_20 in FIG. 12) having athickness of 20 nm and formed through continuous sputtering through theuse of the ECR sputtering apparatus; a multilayer CVD insulating film(indicated as ALCVD_15 in FIG. 12) having a thickness of 15 nm andformed through performing the step of forming a thin alumina film by lowpressure CVD a plurality of times; and a multilayer CVD insulating film(indicated as ALCVD_20 in FIG. 12) having a thickness of 20 nm andformed through performing the step of forming a thin alumina film by lowpressure CVD a plurality of times.

[0110] As shown in FIG. 12, the alumina film formed through continuoussputtering through the use of the ECR sputtering apparatus had aninsulation strength of about 5 volts when the thickness was 20 nm, andan insulation strength of about 3 volts when the thickness was 15 nm.Either case was unpractical since the film was likely to suffer staticdamage. In contrast, the miltilayer CVD insulating film had aninsulation strength of 7 volts or greater when the thickness was either20 nm or 15 nm, and it was unlikely to suffer static damage.

[0111] According to the embodiment thus described, each of the shieldgap films 4 a and 7 a is made of the multilayer CVD insulating film madeup of a plurality of thin alumina films stacked that are formed by CVD.As described above, the multilayer CVD insulating film is closely packedand has an even thickness, greater insulation strength and excellentstep coverage. It is thus possible to reduce the thickness thereof. As aresult, according to the embodiment, it is possible to make thethickness of each of the shield gap films 4 a and 7 a smaller than thatof a prior-art shield gap film, and to reduce the shield gap length.Furthermore, a reduction in the shield gap length results in a reductionin half width of the reading output. It is thereby possible to improvethe recording density. FIG. 13 illustrates an example of waveform ofreading output of the thin-film magnetic head of the embodiment, whereinPW50 indicates the half width of the reading output. The half width PW50is a period of time required for the reading output to reach 50% orgreater of the peak value.

[0112] The shield gap film 7 a is formed in regions having projectionsand depressions, such as the neighborhood of the pattern edge of the GMRelement 5 or the neighborhood of the conductive layers 6 connected tothe GMR element 5. Therefore, pinholes and faulty insulation are likelyto result if step coverage is unsatisfactory. In this embodiment,however, the shield gap film 7 a is made of the multilayer CVDinsulating film that exhibits excellent step coverage. It is therebypossible to prevent pinholes and faulty insulation in the shield gapfilm 7 a.

[0113] According to the embodiment, the shield gap films 4 a and 7 athat are thin and have high qualities are formed. It is thereby possibleto improve the yield of thin-film magnetic heads for high densityrecording.

[0114] The foregoing features of the embodiment improve the performancecharacteristics and yield of thin-film magnetic heads.

[0115] In the embodiment not only the shield gap films 4 a and 7 a butalso the shield gap films 4 b and 7 b and the recording gap layer 9 maybe made of multilayer CVD insulating films. It is thereby possible toreduce the thickness of these layers and to improve the qualitiesthereof, and to further improve the characteristics and yield ofthin-film magnetic heads.

Second Embodiment

[0116] Reference is now made to FIG. 14A and FIG. 14B to describe athin-film magnetic head and a method of manufacturing the same of asecond embodiment of the invention. FIG. 14A is a cross sectionorthogonal to the air bearing surface. FIG. 14B is a cross section ofthe pole portions of the head parallel to the air bearing surface.

[0117] In place of the top shield layer 8 of the first embodiment, thethin-film magnetic head of the second embodiment comprises: a top shieldlayer 8 a made of a magnetic material; an isolation film 20; and abottom pole layer 8 b made of a magnetic material. The isolation film 20is an insulating film that magnetically isolates the reproducing headand the recording head from each other.

[0118] In the method of the second embodiment, the top shield layer 8 ais formed on the shield gap films 7 a and 7 b. Next, the isolation film20 is formed on the top shield layer 8 a. The bottom pole layer 8 b isthen formed on the isolation film 20. The isolation film 20 has athickness of 0.1 to 0.2 μm, for example.

[0119] The isolation film 20 is made of a multilayer CVD insulating filmmade up of a plurality of thin alumina films stacked that are formed byCVD, which is similar to the shield gap films 4 a and 7 a of the firstembodiment.

[0120] According to the second embodiment, the isolation film 20magnetically isolates the reproducing head and the recording head fromeach other. It is thereby possible to reduce noise such as Barkhausennoise of the reproducing head resulting from a writing operation of therecording head, and to reduce variations in reading output.

[0121] According to the embodiment, the isolation film 20 is made of themultilayer CVD insulating film. The isolation film 20 is therefore thinand of high quality. It is thus possible to improve the performancecharacteristics and yield of thin-film magnetic heads.

[0122] The remainder of configuration, functions and effects of theembodiment are similar to those of the first embodiment.

Third Embodiment

[0123] Reference is now made to FIG. 15A and FIG. 15B to describe athin-film magnetic head and a method of manufacturing the same of athird embodiment of the invention. FIG. 15A is a cross sectionorthogonal to the air bearing surface. FIG. 15B is a cross section ofthe pole portions of the head parallel to the air bearing surface.

[0124] In place of the photoresist layer 11 and the insulating layer 13of the first embodiment, the thin-film magnetic head of the thirdembodiment comprises a photoresist layer 31 and a coil insulating layer32. The photoresist layer 31 is not formed between the recording gaplayer 9 and the thin-film coil 10, but formed only between the recordinggap layer 9 and a part of the pole portion layer 12 a of the top polelayer 12. In this embodiment the coil 10 is located on the recording gaplayer 9. The coil insulating layer 32 covers the coil 10 and insulatesneighboring ones of the turns of the coil 10 from each other. In thisembodiment an end of the photoresist layer 31 facing toward the airbearing surface 30 defines the throat height.

[0125] The coil insulating layer 32 is made of a multilayer CVDinsulating film made up of a plurality of thin alumina films stackedthat are formed by CVD, which is similar to the shield gap films 4 a and7 a of the first embodiment.

[0126] In the method of the third embodiment, the photoresist layer 31is formed on the recording gap layer 9. Next, the pole portion layer 12a of the top pole layer 12 is formed on the recording gap layer 9 andthe photoresist layer 31. At the same time, the magnetic layer 12 b isformed in the contact hole formed in the recording gap layer 9. Next,the recording gap layer 9 and a part of the top shield layer 8 areetched by ion milling, for example, with the pole portion layer 12 a asa mask. A trim structure is thereby formed. Next, the thin-film coil 10is formed on the recording gap layer 9. The coil insulating layer 32 ofa multilayer CVD insulating film is then formed over the entire surface.The coil insulating layer 32 is polished through CMP, for example, tothe surfaces of the pole portion layer 12 a and the magnetic layer 12 b,and flattened. The following steps are similar to those of the firstembodiment.

[0127] According to the embodiment, the coil insulating layer 32insulating neighboring ones of the turns of the coil 10 from each otheris made of the multilayer CVD insulating film that exhibits excellentstep coverage. As a result, the insulating film without keyholes andvoids is formed to fill the space between neighboring ones of the turnsof the coil 10. It is thereby possible to improve the performancecharacteristics and yield of thin-film magnetic heads.

[0128] The remainder of configuration, functions and effects of thethird embodiment are similar to those of the first embodiment.

[0129] The present invention is not limited to the foregoing embodimentsbut may be practiced in still other ways. For example, the invention isnot limited to a thin-film magnetic head in which the MR element is aGMR element but may be applied to a thin-film magnetic head in which theMR element is an AMR element or a tunnel magnetoresistive (TMR) element.

[0130] In the foregoing embodiments, the thin-film magnetic head isdisclosed, comprising the MR element for reading formed on the base bodyand the induction-type electromagnetic transducer for writing stacked onthe MR element. Alternatively, the MR element may be stacked on theelectromagnetic transducer.

[0131] That is, the induction-type electromagnetic transducer forwriting may be formed on the base body and the MR element for readingmay be stacked on the transducer. Such a structure may be achieved byforming a magnetic film functioning as the top pole layer of theforegoing embodiments as a bottom pole layer on the base body, andforming a magnetic film functioning as the bottom pole layer of theembodiments as a top pole layer facing the bottom pole layer with therecording gap film in between. In this case it is possible that the toppole layer of the induction-type electromagnetic transducer functions asthe bottom shield layer of the MR element, too.

[0132] The invention may be applied to a thin-film magnetic headdedicated to reading that has no induction-type electromagnetictransducer, a thin-film magnetic head dedicated to writing that has aninduction-type electromagnetic transducer only, or a thin-film magnetichead that performs reading and writing with an induction-typeelectromagnetic transducer.

[0133] According to the first thin-film magnetic head or the method ofmanufacturing the same of the invention thus described, at least one ofthe first and second shield gap films is made of a plurality ofinsulating films stacked that are formed by chemical vapor deposition.It is thereby possible to improve the quality of at least one of thefirst and second shield gap films, and to improve the performancecharacteristics and yield of thin-film magnetic heads. In addition, theinvention achieves a reduction in shield gap length. Recording densityis thereby improved.

[0134] According to the second thin-film magnetic head or the method ofmanufacturing the same of the invention, the gap layer of the recordinghead is made of a plurality of insulating films stacked that are formedby chemical vapor deposition. The gap layer is thus made of a highquality insulating film. It is thereby possible to improve theperformance characteristics and yield of thin-film magnetic heads.

[0135] According to the third thin-film magnetic head or the method ofmanufacturing the same of the invention, the isolation film isolatingthe reproducing head from the recording head is made of a plurality ofinsulating films stacked that are formed by chemical vapor deposition.The isolation film is thus made of a high quality insulating film. It isthereby possible to improve the performance characteristics and yield ofthin-film magnetic heads.

[0136] According to the fourth thin-film magnetic head or the method ofmanufacturing the same of the invention, the coil insulating layerinsulating neighboring ones of turns of the thin-film coil from eachother is made of a plurality of insulating films stacked that are formedby chemical vapor deposition. The coil insulating layer is thus made ofa high quality insulating film. It is thereby possible to improve theperformance characteristics and yield of thin-film magnetic heads.

[0137] Obviously many modifications and variations of the presentinvention are possible in the light of the above teachings. It istherefore to be understood that within the scope of the appended claimsthe invention may be practiced otherwise than as specifically described.

What is claimed is:
 1. A thin-film magnetic head comprising: a mediumfacing surface that faces toward a recording medium; a magnetoresistiveelement; a first shield layer and a second shield layer for shieldingthe magnetoresistive element, the shield layers having portions locatedon a side of the medium facing surface and opposed to each other, themagnetoresistive element being placed between these portions of theshield layers; a first shield gap film, provided between themagnetoresistive element and the first shield layer, for insulating themagnetoresistive element and the first shield layer from each other; anda second shield gap film, provided between the magnetoresistive elementand the second shield layer, for insulating the magnetoresistive elementand the second shield layer from each other; wherein at least one of thefirst and second shield gap films is made of a plurality of insulatingfilms stacked that are formed by chemical vapor deposition.
 2. Thethin-film magnetic head according to claim 1 wherein the insulatingfilms formed by the chemical vapor deposition are alumina films.
 3. Amethod of manufacturing a thin-film magnetic head comprising: a mediumfacing surface that faces toward a recording medium; a magnetoresistiveelement; a first shield layer and a second shield layer for shieldingthe magnetoresistive element, the shield layers having portions locatedon a side of the medium facing surface and opposed to each other, themagnetoresistive element being placed between these portions of theshield layers; a first shield gap film, provided between themagnetoresistive element and the first shield layer, for insulating themagnetoresistive element and the first shield layer from each other; anda second shield gap film, provided between the magnetoresistive elementand the second shield layer, for insulating the magnetoresistive elementand the second shield layer from each other; the method including thesteps of: forming the first shield layer; forming the first shield gapfilm on the first shield layer; forming the magnetoresistive element onthe first shield gap film; forming the second shield gap film on themagnetoresistive element; and forming the second shield layer on thesecond shield gap film; wherein at least one of the first and secondshield gap films is formed by stacking a plurality of insulating filmsformed by chemical vapor deposition.
 4. The method according to claim 3wherein the insulating films formed by the chemical vapor deposition arealumina films.
 5. The method according to claim 3 wherein the chemicalvapor deposition is low pressure chemical vapor deposition.
 6. Themethod according to claim 3 wherein the chemical vapor deposition isplasma chemical vapor deposition or atmospheric pressure chemical vapordeposition.
 7. The method according to claim 3 wherein the insulatingfilms formed by the chemical vapor deposition are formed through the useof a plurality of chambers.
 8. The method according to claim 3 whereinthe insulating films formed by the chemical vapor deposition are formedthrough intermittently injecting a material for making the films.
 9. Themethod according to claim 8 wherein the insulating films formed by thechemical vapor deposition are alumina films formed throughintermittently injecting H₂O, N₂O or H₂O₂ which is the material formaking the films and Al(CH₃)₃ or AlCl₃ which is the material for makingthe films in an alternate manner.
 10. The method according to claim 3wherein the insulating films formed by the chemical vapor deposition areformed at a temperature in a range of 100 to 350° C.
 11. A thin-filmmagnetic head comprising: a medium facing surface that faces toward arecording medium; a first magnetic layer including a pole portion and asecond magnetic layer including a pole portion, the first and secondmagnetic layers being magnetically coupled to each other, the poleportions being opposed to each other and placed in regions of themagnetic layers on a side of the medium facing surface, each of themagnetic layers including at least one layer; a gap layer providedbetween the pole portions of the first and second magnetic layers; and athin-film coil at least a part of which is placed between the first andsecond magnetic layers, the at least part of the coil being insulatedfrom the first and second magnetic layers; wherein the gap layer is madeof a plurality of insulating films stacked that are formed by chemicalvapor deposition.
 12. The thin-film magnetic head according to claim 11wherein the insulating films formed by the chemical vapor deposition arealumina films.
 13. A method of manufacturing a thin-film magnetic headcomprising: a medium facing surface that faces toward a recordingmedium; a first magnetic layer including a pole portion and a secondmagnetic layer including a pole portion, the first and second magneticlayers being magnetically coupled to each other, the pole portions beingopposed to each other and placed in regions of the magnetic layers on aside of the medium facing surface, each of the magnetic layers includingat least one layer; a gap layer provided between the pole portions ofthe first and second magnetic layers; and a thin-film coil at least apart of which is placed between the first and second magnetic layers,the at least part of the coil being insulated from the first and secondmagnetic layers; the method including the steps of: forming the firstmagnetic layer; forming the gap layer on the first magnetic layer;forming the second magnetic layer on the gap layer; and forming thethin-film coil; wherein the gap layer is formed by stacking a pluralityof insulating films formed by chemical vapor deposition.
 14. The methodaccording to claim 13 wherein the insulating films formed by thechemical vapor deposition are alumina films.
 15. The method according toclaim 13 wherein the chemical vapor deposition is low pressure chemicalvapor deposition.
 16. The method according to claim 13 wherein thechemical vapor deposition is plasma chemical vapor deposition oratmospheric pressure chemical vapor deposition.
 17. The method accordingto claim 13 wherein the insulating films formed by the chemical vapordeposition are formed through the use of a plurality of chambers. 18.The method according to claim 13 wherein the insulating films formed bythe chemical vapor deposition are formed through intermittentlyinjecting a material for making the films.
 19. The method according toclaim 18 wherein the insulating films formed by the chemical vapordeposition are alumina films formed through intermittently injectingH₂O, N₂O or H₂O₂ which is the material for making the films and Al(CH₃)₃or AlCl₃ which is the material for making the films in an alternatemanner.
 20. The method according to claim 13 wherein the insulatingfilms formed by the chemical vapor deposition are formed at atemperature in a range of 100 to 350° C.
 21. A thin-film magnetic headcomprising: a medium facing surface that faces toward a recordingmedium; a reproducing head incorporating: a magnetoresistive element; afirst shield layer and a second shield layer for shielding themagnetoresistive element, the shield layers having portions located on aside of the medium facing surface and opposed to each other, themagnetoresistive element being placed between these portions of theshield layers; a first shield gap film, provided between themagnetoresistive element and the first shield layer, for insulating themagnetoresistive element and the first shield layer from each other; anda second shield gap film, provided between the magnetoresistive elementand the second shield layer, for insulating the magnetoresistive elementand the second shield layer from each other; a recording headincorporating: a first magnetic layer including a pole portion and asecond magnetic layer including a pole portion, the first and secondmagnetic layers being magnetically coupled to each other, the poleportions being opposed to each other and placed in regions of themagnetic layers on a side of the medium facing surface, each of themagnetic layers including at least one layer; a gap layer providedbetween the pole portions of the first and second magnetic layers; and athin-film coil at least a part of which is placed between the first andsecond magnetic layers, the at least part of the coil being insulatedfrom the first and second magnetic layers; and an isolation film formagnetically isolating the reproducing head and the recording head fromeach other; wherein the isolation film is made of a plurality ofinsulating films stacked that are formed by chemical vapor deposition.22. The thin-film magnetic head according to claim 21 wherein theinsulating films formed by the chemical vapor deposition are aluminafilms.
 23. A method of manufacturing a thin-film magnetic headcomprising: a medium facing surface that faces toward a recordingmedium; a reproducing head incorporating: a magnetoresistive element; afirst shield layer and a second shield layer for shielding themagnetoresistive element, the shield layers having portions located on aside of the medium facing surface and opposed to each other, themagnetoresistive element being placed between these portions of theshield layers; a first shield gap film, provided between themagnetoresistive element and the first shield layer, for insulating themagnetoresistive element and the first shield layer from each other; anda second shield gap film, provided between the magnetoresistive elementand the second shield layer, for insulating the magnetoresistive elementand the second shield layer from each other; a recording headincorporating: a first magnetic layer including a pole portion and asecond magnetic layer including a pole portion, the first and secondmagnetic layers being magnetically coupled to each other, the poleportions being opposed to each other and placed in regions of themagnetic layers on a side of the medium facing surface, each of themagnetic layers including at least one layer; a gap layer providedbetween the pole portions of the first and second magnetic layers; and athin-film coil at least a part of which is placed between the first andsecond magnetic layers, the at least part of the coil being insulatedfrom the first and second magnetic layers; and an isolation film formagnetically isolating the reproducing head and the recording head fromeach other; the method including the steps of: forming the reproducinghead; forming the recording head; and forming the isolation film;wherein the isolation film is formed by stacking a plurality ofinsulating films formed by chemical vapor deposition.
 24. The methodaccording to claim 23 wherein the insulating films formed by thechemical vapor deposition are alumina films.
 25. The method according toclaim 23 wherein the chemical vapor deposition is low pressure chemicalvapor deposition.
 26. The method according to claim 23 wherein thechemical vapor deposition is plasma chemical vapor deposition oratmospheric pressure chemical vapor deposition.
 27. The method accordingto claim 23 wherein the insulating films formed by the chemical vapordeposition are formed through the use of a plurality of chambers. 28.The method according to claim 23 wherein the insulating films formed bythe chemical vapor deposition are formed through intermittentlyinjecting a material for making the films.
 29. The method according toclaim 28 wherein the insulating films formed by the chemical vapordeposition are alumina films formed through intermittently injectingH₂O, N₂O or H₂O₂ which is the material for making the films and Al(CH₃)₃or AlCl₃ which is the material for making the films in an alternatemanner.
 30. The method according to claim 23 wherein the insulatingfilms formed by the chemical vapor deposition are formed at atemperature in a range of 100 to 350° C.
 31. A thin-film magnetic headcomprising: a medium facing surface that faces toward a recordingmedium; a first magnetic layer including a pole portion and a secondmagnetic layer including a pole portion, the first and second magneticlayers being magnetically coupled to each other, the pole portions beingopposed to each other and placed in regions of the magnetic layers on aside of the medium facing surface, each of the magnetic layers includingat least one layer; a gap layer provided between the pole portions ofthe first and second magnetic layers; a thin-film coil at least a partof which is placed between the first and second magnetic layers, the atleast part of the coil being insulated from the first and secondmagnetic layers; and a coil insulating layer for insulating neighboringones of turns of the coil from each other; wherein the coil insulatinglayer is made of a plurality of insulating films stacked that are formedby chemical vapor deposition.
 32. The thin-film magnetic head accordingto claim 31 wherein the insulating films formed by the chemical vapordeposition are alumina films.
 33. A method of manufacturing a thin-filmmagnetic head comprising: a medium facing surface that faces toward arecording medium; a first magnetic layer including a pole portion and asecond magnetic layer including a pole portion, the first and secondmagnetic layers being magnetically coupled to each other, the poleportions being opposed to each other and placed in regions of themagnetic layers on a side of the medium facing surface, each of themagnetic layers including at least one layer; a gap layer providedbetween the pole portions of the first and second magnetic layers; athin-film coil at least a part of which is placed between the first andsecond magnetic layers, the at least part of the coil being insulatedfrom the first and second magnetic layers; and a coil insulating layerfor insulating neighboring ones of turns of the coil from each other;the method including the steps of: forming the first magnetic layer;forming the gap layer on the first magnetic layer; forming the secondmagnetic layer on the gap layer; forming the thin-film coil; and formingthe coil insulating layer; wherein the coil insulating layer is formedby stacking a plurality of insulating films formed by chemical vapordeposition.
 34. The method according to claim 33 wherein the insulatingfilms formed by the chemical vapor deposition are alumina films.
 35. Themethod according to claim 33 wherein the chemical vapor deposition islow pressure chemical vapor deposition.
 36. The method according toclaim 33 wherein the chemical vapor deposition is plasma chemical vapordeposition or atmospheric pressure chemical vapor deposition.
 37. Themethod according to claim 33 wherein the insulating films formed by thechemical vapor deposition are formed through the use of a plurality ofchambers.
 38. The method according to claim 33 wherein the insulatingfilms formed by the chemical vapor deposition are formed throughintermittently injecting a material for making the films.
 39. The methodaccording to claim 38 wherein the insulating films formed by thechemical vapor deposition are alumina films formed throughintermittently injecting H₂O, N₂O or H₂O₂ which is the material formaking the films and Al(CH₃)₃ or AlCl₃ which is the material for makingthe films in an alternate manner.
 40. The method according to claim 33wherein the insulating films formed by the chemical vapor deposition areformed at a temperature in a range of 100 to 350° C.